KR102503988B1 - Motor Control Methods and Devices for Shift-By-Wire Systems - Google Patents

Abstract

Disclosed is a method and apparatus for controlling a motor of an electric shift-by-wire (SBW) system in which shift range switching of an automatic transmission is implemented by a switched reluctance motor (SR motor). In the motor control method of an electric shift-by-wire system according to the present invention, when a shift range change request is input, the current position of the SR motor is recognized as the starting position at the time when the shift request is input, and the current position and the target position of the SR motor are If the current position and target position do not match, apply current to rotate the SR motor in the direction of the target position, and operate the counter from the time the current is applied until the actual movement of the SR motor is detected. counts the time of, compares the counted time with a preset time reference value, and performs an advance control to speed up the rotational speed of the SR motor when the counted time exceeds the time reference value, and the SR motor rotates toward the target position The main purpose of the present invention is to measure the current applied to the SR motor in the actual speed range and increase the advance control or perform the retard control to slow down the rotational speed of the SR motor according to the measured current value.

Description

Motor control method and device of electric shift-by-wire system {Motor Control Methods and Devices for Shift-By-Wire Systems}

The present invention relates to a method and apparatus for controlling a motor of an electric shift by wire system (SBW, Shift By Wire), and more particularly, to a method and apparatus for controlling a motor of an electric shift by wire system using a switched reluctance motor (SR motor) as a shift actuator It is about.

In the SBC (Shift-By-Cable) method, which is a shift range conversion method of an existing automatic transmission, when the shift lever is moved, the detent plate is rotated by the cable, the manual valve is moved, and the P, R, N, and D flow paths on the valve body are moved. Switching to the desired shift range is implemented by opening . However, since the existing SBC method has to consider the position or arrangement of cables, there are disadvantages in that the design limitations are large and assembly and mass productivity are poor.

A method to replace the existing SBC method is the SBW (Shift By Wire) method. The SBW method is a technology that provides operation convenience and improves safety by rotating the detent plate with a motor instead of a cable connected to the shift lever in the driver's seat. This is configured to detect the operating condition of the shift lever with a sensor or switch, and operate the manual valve by rotating the detent plate with a motor. In electric vehicles and DCT systems without a hydraulic circuit, the function of engaging and disengaging the parking gear is simply performed.

In the shift by wire (SBW) method, the detent plate has a plurality of shift ranges in which the detent roller can be statically stabilized by a detent spring. The motor rotates the detent plate to an appropriate position in response to the driver's request to change the shift range according to the driver's operation of the shift lever, and establishes the driver's desired state, such as parking and driving, by engaging a specific mechanical state of the vehicle system.

When the driver inputs the desired shift range through the shift lever, the vehicle controller receives it, determines the control value of the motor (control value including the rotation direction and rotation angle (displacement amount of the detent plate)), and uses the determined control value. It takes some time to drive the motor and make the actual range connection state. This is usually due to the responsiveness of the motor.

Even the driver can immediately check the responsiveness of the motor when changing the shift range. This is because there is a slight time difference between the point at which the shift lever operation is completed and the point at which range information is displayed through a cluster after actual range engagement. However, if the response is not uniform, it may cause a quality problem and lead to a weakening of the marketability of the vehicle.

In the case of a general BLDC motor, speed feedback control using PWM (Pulse Width Modulation) duty control is possible, so the non-uniform response problem can be solved. However, SR motors (Switched Reluctance Motors) have advantages in terms of cost, but due to their characteristics, variable PWM duty control is not possible. Therefore, when applying SR motors, technology that can guarantee uniformity of response (constant shifting time) is required. The situation is.

Korean Patent Publication No. 2015-0062167 (published on 2015. 06. 05)

The technical problem to be solved by the present invention is to ensure uniformity of response (constant shift time) only by changing software without adding or changing additional hardware in an electric shift-by-wire system using a SR motor (Switched Reluctance Motor) as a shift actuator It is intended to provide a method and apparatus for controlling a motor of an electric shift-by-wire system capable of

According to one aspect of the present invention as a means of solving the problem,

In an electric shift-by-wire (SBW) system in which shift range switching of an automatic transmission is implemented by a switched reluctance motor (SR motor),

(a) recognizing the current position of the SR motor as a starting position at the time when the shift request is input when a shift range switching request is input, and determining whether the current position of the SR motor and a target position coincide with each other;

(b) applying a current to rotate the SR motor in the direction of the target position when the current position and the target position do not match;

(c) counting the time from when the current is applied to when the actual motion of the SR motor is detected by operating a counter;

(d) comparing the counted time with a preset time reference value, and performing advance control to increase the rotational speed of the SR motor when the counted time exceeds the time reference value; and

(e) Measure the current applied to the SR motor in the actual speed range in which the SR motor rotates toward the target position, and increase the advance control or slow down the rotation speed of the SR motor according to the measured current value. It provides a motor control method of an electric shift-by-wire system including the step of doing.

The motor control method of the electric shift by-wire system according to an aspect of the present invention also includes,

(d') comparing the difference between the current position of the SR motor and the starting position after the advance control through step (d) between steps (d) and (e) with a preset threshold; can

Here, as a result of the comparison through the step (d'), if the difference between the current position of the SR motor and the starting position after the advance control is less than a preset threshold, return to the step (c) after initializing the counter and repeat the process thereafter However, in the repetitive execution, in the step (d), the advance control that makes the rotational speed of the SR motor faster than the previous advance control is executed, and the difference between the current position of the SR motor and the starting position after the advance control exceeds a preset threshold If exceeded, it can be programmed to switch the process to step (e) above.

Also, in step (e), advance control may be increased or retard control may be performed by comparing the measured current value with a preset reference current value.

Preferably, in step (e), a current error value (current error value = reference current value - measured current value) is calculated by subtracting the measured current value from the reference current value, and the current error value is compared with a set threshold value. It may be set so that the advance control is increased in proportion to the increase and the retardation control is performed in proportion to the decrease.

According to another aspect of the present invention as a means of solving the problem,

a switched reluctance motor (SR motor) generating a driving force for rotating the detent plate to a target position;

an encoder outputting a corresponding electrical signal according to rotation of the SR motor;

The target position is set by analyzing the signal from the shift lever sensor that detects the position change of the shift lever, and the drive of the SR motor is controlled based on the encoder signal so that the detent plate can be rotated toward the set target position. Including; SBW controller (Shift By Wire Controller) to

The SBW controller,

When a shift range change request is input according to the driver's manipulation of the shift lever, current is applied to the SR motor, the time from when the current is applied to the time when the actual movement of the SR motor is detected is counted, and the counted time is When the preset time value is exceeded, advance control is executed to speed up the rotational speed of the SR motor, and the current applied to the SR motor is measured in the actual speed range in which the SR motor rotates toward the target position. Provided is a motor control device for an electric shift-by-wire system having a plurality of processors programmed to increase the advance control or execute retard control that slows down the rotational speed of the SR motor.

Here, the plurality of processors preferably,

a determination unit for recognizing a current position of the SR motor as a start position when a shift range switching request is input and determining whether the current position of the SR motor and a target position match;

a current controller for applying a current to rotate the SR motor in the direction of the target position when the current position and the target position do not match as a result of the determination by the determination unit;

a counter unit which counts the time from when the current is applied by the current control unit to when the actual movement of the SR motor is sensed by activating the counter; and

A comparison unit for comparing the time counted by the counter unit with a preset time reference value;

The current controller,

When the time counted by the counter unit exceeds the time reference value, an advance control is performed to increase the rotational speed of the SR motor;

and logic programmed to further increase the advance control or perform retard control to slow down the rotational speed of the SR motor according to a current value measured in an actual speed range in which the SR motor rotates toward a target position.

According to an embodiment of the present invention, in an electric shift-by-wire system using a SR motor (Switched Reluctance Motor) as a shift actuator, uniformity of response (constant shift time) can be guaranteed only by changing software without additional hardware addition or change. Accordingly, it is possible to prevent deterioration in marketability or safety accidents due to shift delay.

1 is a perspective view showing a range switching mechanism of a shift-by-wire system applied to an automatic transmission;
2 is a schematic diagram of a motor control device of a shift-by-wire system according to an embodiment of the present invention.
3 is a reference diagram of the present invention for explaining advance control;
4 is a control flowchart showing a series of processes for controlling a motor in a shift-by-wire system in order;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

In describing the present invention, terms used in the following specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In addition, the terms "include" or "having" in this specification are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other It should be understood that the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Also, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

In addition, terms such as "...unit", "...unit", and "...module" described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. can

In the description with reference to the accompanying drawings, the same reference numerals will be assigned to the same components, and duplicate descriptions of the same components will be omitted. In addition, in the description of the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

First, with reference to FIG. 1, the mechanical configuration of the shift range switching mechanism of the shift-by-wire system will be schematically reviewed.

1 is a perspective view showing a shift range switching mechanism of a shift-by-wire system applied to an automatic transmission.

Referring to FIG. 1 , the shift range switching mechanism 13 includes a detent plate 15 interlocked to determine the position of the spool 42a of the manual valve 42 and a driving force for rotating the detent plate 15 It includes a shift actuator 16 that generates. The shift actuator 16 may be electric, and like a starter motor (not shown), it operates by receiving power from a battery installed in a vehicle.

The shift range switching mechanism 13 is interlockingly connected with the parking mechanism 17 . The detent plate 15 of the shift range switching mechanism 13 is rotated by the shift actuator 16 to step by step the spool 42a of the manual valve 42 or the parking rod 17c of the parking mechanism 17. Push and pull to determine position. At this time, the detent mechanism is composed of the detent plate 15, the rotating shaft 15a, and the detent spring 15b.

The detent spring 15b may be supported on the valve body 42b of the manual valve 42, and the detent plate 15 may be formed in an approximate fan shape. The rotation center of the detent plate 15 is mechanically connected to the shift actuator 16 via the rotation shaft 15a. Accordingly, the detent plate 15 rotates in synchronization with the motor 16a of the shift actuator 16 .

A shift range determining surface (150, hereinafter referred to as a 'positioning surface') made of continuous curved waveforms is formed on the outer circumference of the detent plate 15, and a detent spring is formed at a specific position of the positioning surface 150. The roller 15c of (15b) can be seated and maintained in a positioned state (shift range switching state).

Preferably, four valleys may be formed on the positioning surface corresponding to each range position (P, R, N, D) of the interlocking manual valve 42. A mountain is formed between each valley and a neighboring valley, for example, between a P-range valley and an R-range valley, or between an R-range valley and an N-range valley. In this case, the mountain means a boundary between adjacent shift ranges.

The pitch between the valley determining the position of each shift range and the neighboring valley is the same, so the pitch between the mountain representing the boundary between the adjacent shift ranges and the neighboring mountain is also the same. Of course, in some cases, the pitch between the P-range goal and the R-range goal may be made larger than the pitch between other goals. Therefore, the pitch between all goals is not the same.

The shift actuator 16 is driven by the signal output when the driver operates the shift lever 11, and accordingly, any one of the four valleys (the valleys determining the position of each range of P, R, N, and D) The roller 15c of the detent spring 15b is located in the valley of Due to this, the detent plate 15 remains positioned at a position corresponding to each position of the manual valve 42 .

The shift actuator 16 includes an electric motor, more specifically, an SR motor (Switched Reluctance Motor, 16a, hereinafter referred to as 'motor' for convenience of description), a reduction mechanism 16b for decelerating its rotation, and a motor ( 16a) may include an encoder 16c that senses the rotation direction and rotation angle according to rotation and outputs corresponding electrical signals to the SBW controller 14 to be described later.

The rotating shaft 15a may be integrally rotatably connected to the output shaft (not shown) of the speed reduction mechanism 16b by splines or the like, and the parking mechanism 17 locks the output shaft 10 of the automatic transmission 1 non-rotatably. ) state or rotatable Un-Lock state. The parking mechanism 17 may include a parking gear 17a on the outer surface of the output shaft 10, a parking lock pawl 17b, a parking rod 17c, and the like.

The basic operation of the shift range switching mechanism 13 configured as described above will be briefly reviewed.

One of the parking range (P), reverse range (R), neutral range (N), and drive range (D) of the automatic transmission (1) by the driver of the vehicle operating the shift lever (11) or the parking switch (12). A range of is selected. As a result, a signal is output from the shift lever sensor 103 or parking switch 12, and the SBW controller 14 receives the output signal and recognizes the selected target position (or target range, P, R, N, D) do.

The SBW controller 14 generates command values (duty values as control values including rotation direction and rotation angle) of the shift actuator 16 based on distance information between the current position and the newly recognized target positions (P, R, N, and D). ) is determined, and the motor 16a is rotated forward or backward by a predetermined angle at a timing set based on the determined command value. As a result, the rotating shaft 15a and the detent plate 15 are rotated at a predetermined angle.

Here, the timing may be determined by a Hall sensor (not shown) using a Hall element installed inside the motor and having a current magnetic effect, and the encoder 16c senses the signal change according to the rotation of the motor 16a and the current speed change A signal corresponding to the range is provided to the SBW controller 14. The SBW controller 14 feedback-controls the motor 16a based on signals from the encoder 16c and the hall sensor 16d.

For example, when the shift lever 11 is operated from the neutral range N to the drive range D, the target position signal changes from N to D. Upon receiving this signal, the SBW controller 14 sets a target rotation angle corresponding to the selected target position D, determines a command value (duty value) corresponding thereto, and permits power to the motor 16a as much as the determined command value. do.

The SBW controller 14 also receives a signal corresponding to the rotation angle from the encoder 16c in real time when the motor 16a is driven and the output shaft rotates according to energization. In addition, the rotation angle and direction of the motor 16a are recognized in real time from the received signal of the encoder 16c, and the rotation angle of the motor 16a is feedback-controlled so that the rotation angle of the motor 16a matches the target rotation angle.

According to this control, the detent plate 15 rotates counterclockwise in the drawing by a predetermined angle, so that the roller 15c of the detent spring 15b escapes from the trough of "N" and crosses one adjacent floor. It is located in the valley of "D" of the adjacent side. As a result, the spool 42a of the manual valve 42 slides in the axial direction and the range of the manual valve 42 is switched from N to D.

When the driver manually operates the parking switch 12 to select the parking range P, the rotation of the detent plate 15 pushes the parking rod 17c and lifts the parking lock pawl 17b to A claw 17d is interposed between the teeth of the parking gear 17a. As a result, the output shaft 10 of the automatic transmission 1 is locked, and the manual valve 42 stops at the "P" position.

When the load of the motor increases due to external environmental conditions (eg, cryogenic temperature, deterioration of related parts, etc.), the response speed of the motor is slowed down. However, unlike servo motors, since the SR motor cannot be controlled through feedback through PWM (Pulse Width Modulation) duty control due to its characteristics, a different approach is required to ensure uniform response.

Therefore, according to the present invention, when the motor is operated according to the shift range switching request, the U phase is energized according to the motor's responsiveness (reaction speed) and current information (actually applied current information to the motor) by +1 Task rather than the actual pattern. In the first case, a motor control device of an electric shift-by-wire system is provided to solve the responsiveness problem of the SR motor through motor speed control using the effect of making up for the current rise delay.

Hereinafter, a motor control apparatus of a shift-by-wire system according to an embodiment of the present invention applied to the shift-by-wire system will be described.

2 is a schematic diagram of a motor control device of a shift-by-wire system according to an embodiment of the present invention.

Referring to FIG. 2 , the motor control device according to an embodiment of the present invention includes the aforementioned motor 16a (SR motor), encoder 16c, and SBW controller 14. The motor 16a rotates the detent plate 15 to the target position under the control of the SBW controller 14, and the SBW controller determines whether the detent plate 15 has entered the target position based on the signal from the encoder 16c. (14) recognizes.

As described above, the SBW controller 14 analyzes a signal output from the shift lever sensor 103 when the shift lever 11 is operated to set a target position. Then, the motor 16a is controlled to rotate the detent plate 15 toward the set target position. More specifically, the rotation angle of the motor 16a is recognized from the signal of the encoder 16c, and the rotation angle is controlled to match the target rotation angle.

In the present invention, the SBW controller 14 applies current to the motor in response to a shift range change request according to manipulation of the shift lever, but responds based on the time from the time the current is applied to the time the actual movement of the motor is detected. It includes a plurality of processors programmed to determine whether the response is appropriate and to compensate for the responsiveness as an advance control that increases the rotational speed of the motor when the responsiveness is low.

More specifically, when a shift range switching request is input according to the driver's manipulation of the shift lever, current is applied to the motor, but the time from when the current is applied to the time when the actual movement of the motor is detected is counted, If the set time exceeds the preset time reference value, advance control is performed to speed up the rotation speed of the motor. and a plurality of processors programmed to execute a retard control that increases the advance control or slows the rotational speed of the motor.

The plurality of processors preferably recognizes the current position of the motor 16a as a start position at the time when the shift range switching request is input, and determines whether the current position of the motor 16a and the target position match 140 and A current control unit 142 for applying a current for rotating the motor 16a in the direction of the target position when the current position and the target position do not match as a result of the determination by the determination unit 140 is included.

In addition, the counter unit 144 counts the time from the time when the current is applied by the current control unit 142 to the time when the actual movement of the motor 16a is detected by operating the counter, and the counter unit 144 A comparison unit 146 for comparing the counted time with a preset time reference value is included. Here, the time reference value is derived through repeated experiments or simulations of the same simulated environment, and may be a time required to provide optimal responsiveness.

Specifically, the current control unit 142 determines that the time counted by the counter unit 144 (time from when current is applied to the motor 16a to when the movement of the motor 16a is actually detected) exceeds the time reference value. If the actual load is large, it is determined that the drive of the motor 16a is delayed (response is poor), and the program (control) programmed to compensate for the delay in response by increasing the rotational speed of the motor 16a through advance control logic) may be included.

At this time, the program converts the voltage of the shunt resistor into current when the motor 16a enters the actual speed range in which it rotates toward the target position, measured by measuring the current applied to the actual motor 16a. A program may also be included to appropriately adjust the responsiveness of the motor 16a through perceptual control that further increases the advance control or slows down the rotational speed of the motor 16a according to the current value.

For reference, as shown in the reference diagram of FIG. 3, the advance control is the speed of the motor 16a by using the effect of recovering the current rise delay (Delay) when the U-phase is energized before the actual pattern by +1 Task. It means control that raises, and retardation control means control that slows down the speed of the motor 16a by performing energization of the U phase later than the actual pattern by -1 Task.

Hereinafter, a motor control process performed by the motor control device of the above-described electric shift-by-wire system according to an embodiment of the present invention will be described in more detail with reference to a control flowchart of FIG. 4 . For convenience of description, the configurations shown in FIGS. 1 and 2 described above will be described with reference to corresponding reference numerals.

4 is a control flowchart showing a series of motor control processes performed in the motor control device of the electric shift-by-wire system in order.

Referring to FIG. 4 , in the motor control method of the electric shift-by-wire system, when a shift range change request is input, the current position of the motor 16a at the time when the shift request is input is recognized as the starting position, and the motor 16a It starts with determining whether the current location and the target location coincide (S100). In step S100, if the current position and the target position of the motor 16a coincide, it is determined that the shift range switching has already been completed according to the request for shift range switching, and the process ends without further progress.

In contrast, as a result of the determination through step S100, if the current position and the target position do not match, a step of applying a current to the motor 16a to rotate the motor 16a in the direction of the target position (S200) proceeds. In step S200, a target rotation angle is determined based on distance information from the current position to the selected target position (target shift range), and power is allowed until the rotation angle of the motor 16a reaches the target rotation angle do.

When the current for rotating the motor 16a to the target position is applied in step S200, the next step is to count the time from when the current is applied to the time when the actual movement of the motor 16a is detected by operating a counter (S300) proceeds successively. At this time, in step S300, the time when the change in output of the encoder 16c is detected after the current is applied may be recognized as the time when the actual movement of the motor 16a is detected.

The time counted in step S300 is then provided as a comparison value for comparison with a preset time reference value in step S400. Specifically, in step S400, when the time counted in step S300 exceeds the time reference value, it is determined that the rotation speed of the motor 16a is slower than the initial set speed, and the rotation speed of the motor 16a is increased to compensate for the slow reaction speed A predetermined control is performed.

Here, the predetermined control may be an advance control that increases the rotational speed of the motor 16a. At this time, as mentioned above, the advance control means control that increases the speed of the motor 16a by using the effect of recovering the current rise delay (Delay) when the U-phase is energized by +1 Task before the actual pattern ( see Figure 3).

In contrast, if the time counted in step S300 is less than the time reference value, it is determined that the rotational speed of the motor 16a is an appropriate speed, and a predetermined control for increasing the rotational speed of the motor 16a, that is, the advance control Without passing through the step, it is converted to step S500 to be performed later.

After step S400, the process proceeds to step S500 of comparing the difference between the current position of the motor 16a and the starting position with a preset threshold value. In step S500, if the difference between the current position and the starting position of the motor 16a after the advance control is less than a preset threshold value, the motor 16a did not properly move in the direction of the target position despite the advance control, so after the counter initialization step S300 return to

More specifically, as a result of comparison through step S500, if the difference between the current position and the start position of the motor 16a after the advance control is less than a preset threshold, return to step S300 after counter initialization and repeat the process thereafter, In step S400 during repetitive execution, the advance control (for example, U-phase is energized prior to the actual pattern by 2 tasks), which makes the rotational speed of the motor 16a faster than the previous advance control, is performed.

In contrast, as a result of comparison through step S500, if the difference between the current position and the starting position of the motor 16a after the advance control exceeds a preset threshold value, the motor 16a enters the actual speed range in which it rotates toward the target position. Determined to be so, the process is switched to step S600 to be described later.

In step S600, the current applied to the motor 16a is measured in the actual speed range in which the motor 16a rotates toward the target position, and the advance control is increased according to the measured current value or the rotation of the motor 16a is reversed. Perceptual control to slow down is performed. In this step S600, the measured current value is compared with a preset reference current value to further increase the advance control or slow the rotation speed. Perception control may be performed.

Step S600 will be examined in more detail.

When the process is converted to step S600, first, a current error value is calculated (S610). Here, the current error value is a value obtained by subtracting the current value (measured current value) of the motor 16a measured in the actual speed range from the reference current value, that is, from a simple formula such as "current error value = reference current value - measured current value" can be calculated.

In this case, the current value of the motor 16a, which is a reference in calculating the current error value, that is, the reference current value may be set to a different value according to the battery voltage. This is to prevent a current rise due to a battery voltage difference from being mistaken for an increase in the load of the motor 16a.

When the current error value is derived through step S610, it is determined whether the actual rotation angle (calculated from the encoder output) and the target rotation angle of the motor 16a have reached the stop control section of the motor 16a (rotation of the motor 16a). It is determined whether the position is close to the target position) (S620), and when it is determined that the motor 16a has reached the stop control section, the advance control of the motor 16a is stopped and the stop control of the motor 16a is controlled (two-phase energization) is performed so that the motor 16a can be stopped at the target position (S622).

On the other hand, when the motor 16a does not reach the stop control section, the current error value calculated in step S610 is compared with preset threshold values, and advance control is performed in proportion to the current error value as it is larger, and if it is smaller, the current error value is proportional to it. Perceptual control is performed (S630).

For example, as shown in the drawing, the current error value is first compared with the set threshold value 1, which is the largest threshold value, and if the current error value is greater than the set threshold value 1 (current error value > set threshold value 1), the advance control +2 Task is further increased, and if the current error value is less than the set threshold value 1 (current error value <set threshold value 1), it is compared with the set threshold value 2 smaller than the set threshold value 1 once again.

As a result, if the current error value is greater than the set threshold value 2 (set threshold value 1 > current error value > set threshold value 2), the advance control is increased by +1 Task, and if the current error value is less than the set threshold value 2, (Current error value < set threshold value 2) Compared once again with the set threshold value 3 smaller than the set threshold value 2, if the current error value is smaller than the set threshold value 3, the advance control is reduced by -2 Task (- 2 Task perception control).

Conversely, if the current error value is greater than the set threshold value 3, after comparison with the set threshold value 4 greater than the set threshold value 3 and less than the set threshold value 2, if it is smaller than the set threshold value 4 (set threshold value 3 < current error value < Set threshold 4), reduce advance control by -1 task (-1 task tardiness control), and if it is greater than set threshold 4 (set threshold 4 < current error value < set threshold 2), advance or retard control is not performed. It can be set not to.

According to the embodiment of the present invention described above, in an electric shift-by-wire system using a SR motor (Switched Reluctance Motor) as a shift actuator, uniformity of response (constant shift time) can be achieved only by changing software without additional hardware addition or change. Accordingly, it is possible to prevent deterioration in marketability or safety accidents due to shift delay.

In the above detailed description of the present invention, only special embodiments have been described accordingly. However, it should be understood that the present invention is not limited to the particular forms mentioned in the detailed description, but rather it is understood to include all modifications, equivalents and substitutes within the spirit and scope of the present invention as defined by the appended claims. It should be.

10: output shaft 13: range switching mechanism
14: SBW controller 15: detent plate
15a: rotation axis 15b: detent spring
15c: roller 16: shift actuator
16a: motor 16b: reduction mechanism
16c: encoder 17: parking mechanism
140: determination unit 142: current control unit
144: counter unit 146: comparison unit
150: positioning surface

Claims (8)

In an electric shift-by-wire (SBW) system in which shift range switching of an automatic transmission is implemented by a switched reluctance motor (SR motor),
(a) recognizing the current position of the SR motor as a start position at the time when the shift request is input when a shift range switching request is input, and determining whether the current position of the SR motor and a target position coincide with each other;
(b) applying a current to rotate the SR motor in the direction of the target position when the current position and the target position do not match;
(c) counting the time from when the current is applied to when the actual movement of the SR motor is detected by operating a counter;
(d) comparing the counted time with a preset time reference value, and performing advance control to speed up the rotational speed of the SR motor when the counted time exceeds the time reference value; and
(e) Measure the current applied to the SR motor in the actual speed range where the SR motor rotates toward the target position, and increase the advance control or slow down the rotation speed of the SR motor according to the measured current value. Including;
In step (e),
A method for controlling a motor of an electric shift-by-wire system in which an advance control is increased or a retard control is performed by comparing a measured current value with a preset reference current value.
According to claim 1,
(d') comparing the difference between the current position of the SR motor and the starting position after the advance control through the step (d) between steps (d) and (e) with a preset threshold; further comprising Motor control method of electric shift-by-wire system.
According to claim 2,
As a result of the comparison through the step (d'), if the difference between the current position of the SR motor and the starting position after the advance control is less than a preset threshold, return to the step (c) after the counter is initialized and repeat the process thereafter, A method for controlling a motor of an electric shift-by-wire system in which, in step (d), during repetitive execution, an advance control that makes the rotational speed of the SR motor faster than the previous advance control is performed.
According to claim 2,
As a result of the comparison through the step (d'), if the difference between the current position of the SR motor and the starting position after the advance control exceeds a preset threshold value, the motor of the electric shift-by-wire system for switching the process to the step (e) control method.
delete According to claim 1,
Calculate a current error value (current error value = reference current value - measured current value) by subtracting the measured current value from the reference current value;
A motor control method of an electric shift-by-wire system in which the current error value is compared with a set threshold value, and advance control is increased in proportion to the current error value, and retardation control is performed in proportion to the current error value.
a SR motor (Switched Reluctance Motor, 16a) generating a driving force for rotating the detent plate 15 to a target position;
an encoder (16c) outputting a corresponding electrical signal according to the rotation of the SR motor (16a);
A target position is set by analyzing a signal from a shift lever sensor that detects a change in position of the shift lever, and the detent plate 15 is rotated toward the set target position based on the signal of the encoder 16c. Including; SBW controller (Shift By Wire Controller, 14) for controlling the driving of the SR motor (16a),
The SBW controller 14,
When a shift range change request is input according to the driver's operation of the shift lever, current is applied to the SR motor 16a, but the time from when the current is applied to the time when the actual movement of the SR motor 16a is detected is counted and, if the counted time exceeds a preset time reference value, an advance control is executed to speed up the rotational speed of the SR motor 16a. ), and increases the advance control according to the measured current value or performs retardation control to slow down the rotational speed of the SR motor 16a, and compares the measured current value with a preset reference current value A motor control device for an electric shift-by-wire system having a plurality of processors programmed to increase advance control or perform retard control by doing so.
According to claim 7,
The plurality of processors,
a determination unit 140 for recognizing the current position of the SR motor 16a as a start position when a shift range switching request is input and determining whether the current position of the SR motor 16a and a target position match;
a current controller 142 for applying current to rotate the SR motor 16a in the direction of the target position when the current position and the target position do not match as a result of the determination by the determination unit 140;
a counter unit 144 that counts the time from when current is applied by the current control unit 142 to when the actual movement of the SR motor 16a is detected by operating a counter; and
Comparing unit 146 for comparing the time counted by the counter unit 144 with a preset time reference value; including,
The current control unit 142,
When the time counted by the counter unit 144 exceeds the time reference value, an advance control for speeding up the rotational speed of the SR motor 16a is executed;
An electric shift-by-wire system that further increases the advance control or performs retard control that slows down the rotational speed of the SR motor 16a according to the current value measured in the actual speed range in which the SR motor 16a rotates toward the target position. motor control unit.

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